Genotoxic Studies of Some Plant Oil Extracts on Rhyzopertha dominica (Coleoptera: Bostrichidae)

This study was carried out to clarify the genotoxic effects of different concentrations of plant oils of Eruca sativa (Brassicaceae), Zingiber officinale (Zingiberaceae) and Origanum majorana (Lamiaceae) against the conventional organophosphate insecticide (Chlorpyrifos) as synthetic insecticide against Rhyzopertha dominica Fabricius. The R. dominica population was reared for several generations without exposure to any insecticide. Wheat grains were sterilized at a temperature of 55°C for 6hours in order to eliminate any hidden infestation then treated with serial dilutions of Chlorpyrifos and plant oil extracts and given as food to R. dominica for 1, 2, 3, 6 and 8 days. The results indicated that the LC50 values of E. sativa, Z. officinale and O. Majorana were 0.14, 0.23 and 0.32% respectively after 2 days. Genetic variations in DNA fragments after treatment with LC50 and LC25 of E. sativa, Z. officinale and O. majorana were detected by RAPD-PCR analysis using five primers. The results showed distinct DNA polymorphisms or alterations in DNA bands, these alterations were varied according to the examined substances. Chlorpyrifos causes the highest level of DNA alterations (appearance and disappearance DNA bands) followed by E. sativa, Z. officinale and O. majorana respectively. These results were in direct correlation to the difference in mortality effect of the oily extract used. It could be concluded that the plant oil extracts can be used as one of the integrated pest mana...
Source: Journal of Taibah University for Science - Category: Science Source Type: research